Nicotine and stress: Effect on sex hormones and lipid profile in female rats

This work aimed to study the changes in sex hormones and lipid profile in adult female albino rats subjected to treatment with nicotine (N), immobilization stress (S), or their combinations (N+S). These treatments were applied either for one day (T-1) or daily for 10 days (T-10), after which rats in the estrus stage were used for the determination of plasma corticosterone (CS), serum sex hormones as progesterone (P), estrogen (E), FSH, LH and serum lipid profile including total cholesterol (TC), HDL-C, LDL-C, triacylglycerol (TG) and non esterified fatty acids (NEFA). It was clear that either N or S raised plasma CS and serum P levels in both the treatment regimens and that N+S induced a higher level of these hormones compared to each treatment alone. Serum E level was only elevated during T-10 regimen only. An increase in serum LH level was only observed after a single exposure to either N or S, however their combination abolished the stimulatory effect induced by each treatment alone. Serum FSH was not altered by exposure to either N or S alone in both regimens, but in the T-10 regimen their combination significantly lowered FSH level. Regarding the effect on serum lipid profile, serum TC was increased in all T-10 regimen groups. LDL-C was increased by N+S treatment in both regimens, however no change in HDL-C level was observed in all groups. Serum NEFA was increased in all the treated groups during Tio regimen, while in the T-1 regimen NEFA level was only elevated by the combination N+S. Serum TG was insignificantly altered in all the treated groups. The observed changes in the lipid pattern were attributed to the alterations occurred in CS and female sex hormones that caused by N, S or their combinations. (C)1997 The Italian Pharmacological Society.